The present invention relates to a chamber for a vacuum facility comprising at least one opening for the through-transport of workpieces, particularly of circular-disk-shaped workpieces, such as storage disks during their treatment, comprising a transport arrangement, which is movable in a driven manner, for at least one workpiece, to a chamber combination as well as to a method for transporting through at least one disk-shaped workpiece from a respective ring-shaped transport path through an opening inside a vacuum treatment facility.
It is known to transport disk-shaped workpieces, such as storage disks, including, for example, CD's, magnetic storage disks or magneto-optic storage disk, during their treatment in a vacuum treatment facility in which they are treated, for example, by means of non-reactive or reactive processes, such as etching, physical or chemical coating with or without glow discharge support, in a chamber by means of a driven movable transport arrangement along a moving path.
Normally, the workpieces which are transported by the transport arrangement in this manner are fed by a provided linear drive selectively to openings provided on the chamber in order to feed the workpieces in the course of their treatment to additional chambers and stations.
The expenditures for the implementation of linear drives which meet the condition of the vacuum process are relatively high in the case of a desired stroke. In view of the purity requirements to be met, considerable attention must be paid particularly to the formation of particles caused by abrasion.
It is an object of the present invention to provide a chamber of the initially mentioned type in the case of which, for the purpose of a desired stroke, for the charging of a chamber opening with a workpiece, the required expenditures are reduced significantly.
This is achieved by constructing the above-mentioned chamber on the transport arrangement, at least one transport device with a holding device for at least one workpiece is swivellably disposed in a plane perpendicularly to the area of the opening in such a manner that the holding device, transported by means of the transport arrangement into the area of the opening, can be swivelled completely through the opening.
By providing the above-mentioned transport arrangement, it becomes possible to continue to implement a desired moving path for the workpiece in the above-mentioned chamber. By the additional providing of the swivellably disposed transport arrangement with the workpiece holding device on the transport arrangement, a significant advantage is achieved: For sweeping through a curved transport path of a given stroke, a drive may be sufficient which requires considerably less expenditures and space than if the same stroke were to take place linearly. In an extreme case, a rotary drive may be used for the swivel motion. Also, a linear drive, which is changed into a swivel motion, must pass through a much shorter stroke in order to implement the stroke required for charging the opening with the workpiece in comparison to the stroke which a linear drive would have to carry out directly for the charging of the opening.
In a preferred embodiment, the mentioned holding device is constructed in the shape of tongs and can preferably be controlled for the gripping and releasing of a respective workpiece.
This has several advantages, specifically that, on the one hand, the workpiece remains free at least on two sides or even virtually on all sides also inside the holding device and therefore, if the opening of the chamber leads out into a treatment station, such as an etching or coating station, can be treated on two sides or even on all sides. Furthermore, this design is simple, particularly also as far as its releasing and gripping control is concerned.
In addition, as a result, the space required for the swivelling of the workpiece is at most increased insignificantly beyond that required anyway for the workpiece, which permits the optimal adapting of the above-mentioned opening essentially to the dimension of the workpiece to be transported through.
Often, transport arrangements are provided in transport chambers of vacuum treatment facilities whereby the workpiece is displaced at least also linearly to and from the opening to be serviced.
By arranging a swivel bearing for the transport device to be displaced perpendicularly to the area of the opening while being driven linearly, the possibility is created for utilizing an already provided linear drive for the swivel motion of the transport arrangement with the holding device. In addition, the conversion of also an only slight linear advance into a large-angle swivel motion and thus into a large stroke caused by this swivel motion is easy to implement.
Further, for the disk-shaped workpieces, the chamber is preferably constructed such that the disk surfaces of a workpiece held on the holding device are situated in one swivel plane and preferably the diameter of the opening in the swivel plane is considerably longer than in the direction of the swivel axis.
This results in the possibility of implementing the above-mentioned opening only insignificantly wider than given by the dimension of the thickness of the disk-shaped workpiece, which relates to important advantages, for example, with respect to the separation of the atmospheres of the spaces situated on both sides of the mentioned opening.
As mentioned above, as a result of the construction of the chamber according to one embodiment, it becomes possible in a simple manner to implement the swivel drive for the transport arrangement by the linear drive of the transport arrangement.
In addition, in this case the advantage of a linear stroke is maintained although it is relative small, specifically of being able to close off the respective serviced opening to the desired extent.
The suggested chamber may be coupled in a modular manner with one or several known transport chambers with at least two openings or one or several treatment stations, such as etching or coating stations, or with a feeding and a delivery lock-type pass-through chamber or a feeding/delivery lock-type pass-through chamber.
A chamber combination with the above-described chamber according to the invention is achieved by providing that, on its opening, another chamber is arranged in which a rotatably disposed additional transport arrangement for at least one workpiece is provided which has an axis of rotation that is in parallel to the swivel axis of the transport device.
Because of the fact that the swivel axis of the transport arrangement is placed in parallel to the axis of rotation of the additional transport arrangement in the additional chamber provided on the combination, it becomes possible to carry out the guiding of the workpieces through the connection opening essentially radially with respect to the swivel axis in the additional chamber.
Furthermore, because of the fact that the additional transport arrangement in the additional chamber has a majority of holding devices for the workpieces which are jointly rotatable about the above-mentioned axis of rotation essentially in the swivelling plane of the transport arrangement, it becomes possible to feed, from the former chamber, one workpiece after the other to the additional transport arrangement and to return one workpiece after the other through the above-mentioned opening.
As mentioned above, it is known to transport disk-shaped workpieces, such as storage disks, for example, CD's or magnetic storage disks or magneto-optic storage disk, in a vacuum facility on a ring-shaped transport path by means of a transport arrangement. In this respect, reference can be made, for example, to U.S. Patent Document U.S. Pat. No. 3,856,654, German Patent Documents DE-PS 24 54 544, DE-OS 39 12 295 and DE-OS 40 09 603, DE-OS 37 16 498 and European Patent Document EP-A 0 389 820. In this case, the workpieces are moved axially with respect to the ring-shaped transport path through an opening opposite the ring-shaped transport path, for example, in the treatment position.
In the case of a design of a vacuum facility chamber in which, as mentioned above, the transport path of the disk-shaped workpieces is ring-shaped and the workpieces are transported axially in predetermined angular positions of the circular path through provided openings, there is however, an interaction between the depth of such a chamber measured in the axial direction and the possible stroke by means of which the workpieces can be axially transported through.
The reason is that, if the chamber in which the ring-shaped transport path is passed, is to be constructed in a compact and flat manner while including additional axially arranged aggregates, the possible axial stroke will remain small. Analogously, the overall height will become large if considerable travelling paths are to be implemented. In this case, it should be taken into account that if the workpieces are arranged such that they pass through a ring-shaped transport path, the overall height of the respective chamber viewed in the axial direction will have no influence on the number of workpieces arranged along the ring but that this number is determined only by the radial dimension of such a chamber and therefore of the ring-shaped transport path along which additional workpieces are arranged.
It is another object of the present invention to provide a transporting method which eliminates the above-mentioned difficulties.
Because of the fact that the disk-shaped workpieces, with respect to their ring-shaped transport path, are transported radially through the opening, the radial dimension of the ring-shaped transport path can be utilized for the implementation of a required radial stroke, and the circumference of the ring-shaped transport path and of the corresponding chamber can also be used for the arranging of openings.
The implementation of this method according to the invention may take place in many ways, for example, by means of radially acting rams which are fixedly or swivellably aligned with the corresponding openings. However, preferably this method will be implemented by means of the swivellable transport arrangement provided on the initially mentioned chamber according to the invention.
If the transport arrangement provided on the above-mentioned chamber is constructed such that the workpieces are conveyed on a circular path in the chamber, the swivellable transport devices on the transport arrangement will, when it is in each case aligned with one opening, convey a workpiece radially with respect to the axis of rotation of the transport arrangement out of the opening and return it through the opening.
Embodiments of the invention will be explained in the following by means of figures.